The invention discloses a method for preparing beta-carotene. The method comprises the following steps: inoculating a microbial strain for fermentation; adding bio-enzyme for breaking walls 1 to 24 hours before the fermentation is ended; performing solid and liquid separation on a fermentation solution to obtain a wet cell; mixing the wet cell with an organic solvent, and circularly shearing and crushing; performing solid and liquid separation on the mixed solution to obtain an extraction solution; adsorbing the beta-carotene in the extraction solution by using macro-porous adsorption resin; desorbing the macro-porous adsorption resin by using the organic solvent after the adsorption is ended to obtain a desorption solution containing the beta-carotene; removing the solvent from the desorption solution and drying in vacuum to obtain a beta-carotene crystal. According to the method disclosed by the invention, the wet cell is high in wall breaking rate by combination of bio-enzyme wall breaking and mechanical wall breaking; therefore, the extraction rate of the beta-carotene is high; the strain needs not to be dried during extraction, so oxidation of the beta-carotene is avoided. On the other hand, in the method, the macro-porous adsorption resin is used for separating and purifying the beta-carotene, so the process is simple; the mixed oil generated after the beta-carotene is extracted can be recycled as an extraction solvent, so the cost can be lowered, energy consumption can be reduced and environmental protection can be facilitated.